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[texts]Optimal discrimination designs - Holger Dette
We consider the problem of constructing optimal designs for model discrimination between competing regression models. Various new properties of optimal designs with respect to the popular $T$-optimality criterion are derived, which in many circumstances allow an explicit determination of $T$-optimal designs. It is also demonstrated, that in nested linear models the number of support points of $T$-optimal designs is usually too small to estimate all parameters in the extended model...
Downloads: 45
[texts]Optimal reduction - Juan-Pablo Ortega
We generalize various symplectic reduction techniques to the context of the optimal momentum map. Our approach allows the construction of symplectic point and orbit reduced spaces purely within the Poisson category under hypotheses that do not necessarily imply the existence of a momentum map. We construct an orbit reduction procedure for canonical actions on a Poisson manifold that exhibits an interesting interplay with the von Neumann condition previously introduced by the author in his study ...
Downloads: 18
[texts]Optimal Networks - A. O. Ivanov
This mini-course was given in the First Yaroslavl Summer School on Discrete and Computational Geometry in August 2012, organized by International Delaunay Laboratory "Discrete and Computational Geometry" of Demidov Yaroslavl State University. The aim of this mini-course is to give an introduction in Optimal Networks theory. Optimal networks appear as solutions of the following natural problem: How to connect a finite set of points in a metric space in an optimal way? We cover three most natural ...
Downloads: 21
[texts]Objectively discerning Autler-Townes Splitting from Electromagnetically Induced Transparency - Petr M. Anisimov
Autler-Townes splitting (ATS) and electromagnetically-induced transparency (EIT) both yield transparency in an absorption profile, but only EIT yields strong transparency for a weak pump field due to Fano interference. Empirically discriminating EIT from ATS is important but so far has been subjective. We introduce an objective method, based on Akaike's information criterion, to test ATS vs. EIT from experimental data and determine which pertains...
Downloads: 25
[texts]Warm Absorbers in Active Galactic Nuclei - Stefanie Komossa
We first provide a review of the properties of warm absorbers concentrating on what we have learned from ROSAT and ASCA. This includes dusty and dust-free warm absorbers, non-X-ray emission and absorption features of warm absorbers, and the possible warm absorber interpretation of the peculiar 1.1 keV features. We then discuss facets of warm absorbers by a more detailed investigation of individual objects: In a first part, we discuss several candidates for dusty warm absorbers...
Downloads: 11
[texts]Astrophysics in 2005 - V. Trimble
We bring you, as usual, the Sun and Moon and stars, plus some galaxies and a new section on astrobiology. Some highlights are short (the newly identified class of gamma-ray bursts, and the Deep Impact on Comet 9P/ Tempel 1), some long (the age of the universe, which will be found to have the Earth at its center), and a few metonymic, for instance the term "down-sizing" to describe the evolution of star formation rates with redshift.
Downloads: 77
[texts]On Link Availability Probability of Routing Protocols for Urban Scenario in VANETs - S. Kumar
This paper presents the link availability probability. We evaluate and compare the link availability probability for routing protocols; Ad hoc On-demand Distance vector (AODV), Dynamic Source Routing (DSR) and Fisheye State Routing (FSR) for different number of connections and node density. A novel contribution of this work is enhancement in existing parameters of routing protocols; AODV, DSR and FSR as MOD-AODV, MOD-DSR and MOD-FSR...
Downloads: 12
[texts]A remark on the tau-neutrino mass limit - M. M. Guzzo
We point out that the usual experimental upper bounds on the ``tau-neutrino mass'' do not apply if neutrino mixing is considered. The suppression of the population of the tau decay spectrum near the end-point, caused by mixing, may be compensated by an enhancement due to a resonant mechanism of hadronization. It is necessary therefore to analyse the whole spectrum to infer some limit to the ``tau-neutrino mass"...
Downloads: 9
[texts]One Hundred Years of Quantum Physics - Daniel Kleppner
On the occasion of the 100th anniversary of the birth of the quantum idea, the development, achievements, and promises of quantum mechanics are described.
Downloads: 21
[texts]H2 MAGIE: H2 as a Major Agent to Galaxy Interaction and Evolution - Pierre Guillard
Spitzer space telescope spectroscopy reveal a new class of H2-luminous galaxies with enhanced H2 line emission, but where star formation is strongly suppressed. This is in sharp contrast with what is observed in standard star forming galaxies. These sources are all in active phases of galaxy evolution (galaxy interactions, AGN feedback, gas accretion in galaxy clusters, etc.). Why is H2 present in violent phases of galaxy evolution? How is the H2 emission powered? Why is the H2 gas inefficient a...
Downloads: 71
[texts]About Time - M. D. Maia
The concept of time is discussed in the context of the canonical formulation of the gravitational field. Using a hypersurface orthogonal foliation, the arbitrariness of the lapse function is eliminated and the shift vector vanishes, allowing a consistent definition of time.
Downloads: 398
[texts]Conics in normed planes - Ákos G. Horváth
We study the generalized analogues of conics for normed planes by using the following natural approach: It is well known that there are different metrical definitions of conics in the Euclidean plane. We investigate how these definitions extend to normed planes, and we show that in this more general framework these different definitions yield, in almost all cases, different classes of curves.
Downloads: 178
[texts]Parton showering effects in central heavy-boson hadroproduction - M. Deak
If large-angle multigluon radiation contributes significantly to parton showers associated with heavy boson production at the LHC, appropriate parton branching methods are required for realistic Monte Carlo simulations of final states. We report on a study illustrating such effects in the case of central scalar-boson production. We comment on the possible impact of such studies on the modeling of multi-parton interactions.
Downloads: 32
[texts]Twisted planes - Jorge A. Guccione
Let k be a commutative ring. We find and characterize a new family of twisted planes (i. e. associative unitary k-algebra structures on the k-module k[X,Y], having k[X] and and k[Y] as subalgebras).Similar results are obtained for the k-module of two variables power series k[[X,Y]].
Downloads: 330
[texts]Principles and Applications of Difference Imaging - Austin B. Tomaney
The principles of difference imaging outlined and the technique of Alard and Lupton (1997) is generalised to generate the best possible difference images to within the limits of measurement error. It is shown how for a large database of images we can approach diffraction-limited spatial resolution to within measurement error of a combined image. This is achieved through an iterative procedure of difference imaging and deconvolution...
Downloads: 25
[texts]MATLAB codes for teaching quantum physics: Part 1 - Rafael Garcia
Among the ideas to be conveyed to students in an introductory quantum course, we have the pivotal idea championed by Dirac that functions correspond to column vectors (kets) and that differential operators correspond to matrices (ket-bras) acting on those vectors. The MATLAB (matrix-laboratory) programming environment is especially useful in conveying these concepts to students because it is geared towards the type of matrix manipulations useful in solving introductory quantum physics problems...
Downloads: 42
[texts]Acoustic Emission from crumpling paper - Paul A. Houle
From magnetic systems to the crust of the earth, many physical systems that exibit a multiplicty of metastable states emit pulses with a broad power law distribution in energy. Digital audio recordings reveal that paper being crumpled, a system that can be easily held in hand, is such a system. Crumpling paper both using the traditional hand method and a novel cylindrical geometry uncovered a power law distribution of pulse energies spanning at least two decades: (exponent 1.3 - 1.6) Crumpling i...
Downloads: 24
[texts]Heavy Meson Observables - M. A. Ivanov
An accurate and unified description of the non-hadronic electroweak interactions of light- and heavy-mesons is possible when the dressing of quark propagators and the finite size of hadronic bound states is explicitly accounted for.
Downloads: 14
[texts]Entropic Dynamics, Time and Quantum Theory - Ariel Caticha
Quantum mechanics is derived as an application of the method of maximum entropy. No appeal is made to any underlying classical action principle whether deterministic or stochastic. Instead, the basic assumption is that in addition to the particles of interest x there exist extra variables y whose entropy S(x) depends on x. The Schr\"odinger equation follows from their coupled dynamics: the entropy S(x) drives the dynamics of the particles x while they in their turn determine the evolution of S(x...
Downloads: 46
[texts]Variations in Substitution Rate in Human and Mouse Genomes - H. H. von Grünberg
We present a method to quantify spatial fluctuations of the substitution rate on different length scales throughout genomes of eukaryotes. The fluctuations on large length scales are found to be predominantly a consequence of a coarse-graining effect of fluctuations on shorter length scales. This is verified for both the mouse and the human genome. We also found that both species show similar standard deviation of fluctuations even though their mean substitution rate differs by a factor of two...
Downloads: 9
[texts]Robust Estimation of Operational Risk - Nataliya Horbenko
According to the Loss Distribution Approach, the operational risk of a bank is determined as 99.9% quantile of the respective loss distribution, covering unexpected severe events. The 99.9% quantile can be considered a tail event. As supported by the Pickands-Balkema-de Haan Theorem, tail events exceeding some high threshold are usually modeled by a Generalized Pareto Distribution (GPD). Estimation of GPD tail quantiles is not a trivial task, in particular if one takes into account the heavy tai...
Downloads: 165
[texts]Influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors - B. A. Piot
In a recent paper [B. A. Piot et al., Phys. Rev. B 72, 245325 (2005)], we have shown that the lifting of the electron spin degeneracy in the integer quantum Hall effect at high filling factors should be interpreted as a magnetic-field-induced Stoner transition. In this work, we extend the analysis to investigate the influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors...
Downloads: 11
[texts]Weil-Petersson volume of moduli spaces, Mirzakhani's recursion and matrix models - Bertrand Eynard
We show that Mirzakhani's recursions for the volumes of moduli space of Riemann surfaces are a special case of random matrix loop equations, and therefore we confirm again that Kontsevitch's integral is a generating function for those volumes. As an application, we propose a formula for the Weil-Petersson volume Vol(M_{g,0}).
Downloads: 12
[texts]Anatomy of neck configuration in fission decay - S. K. Patra
The anatomy of neck configuration in the fission decay of Uranium and Thorium isotopes is investigated in a microscopic study using Relativistic mean field theory. The study includes $^{236}U$ and $^{232}Th$ in the valley of stability and exotic neutron rich isotopes $^{250}U$, $^{256}U$, $^{260}U$, $^{240}Th$, $^{250}Th$, $^{256}Th$ likely to play important role in the r-process nucleosynthesis in stellar evolution...
Downloads: 25
[texts]SUMSS: A Wide-Field Radio Imaging Survey of the Southern Sky. I. Science goals, survey design and instrumentation - D. C. -J. Bock
The Molonglo Observatory Synthesis Telescope, operating at 843 MHz with a 5 square degree field of view, is carrying out a radio imaging survey of the sky south of declination -30 deg. This survey (the Sydney University Molonglo Sky Survey, or SUMSS) produces images with a resolution of 43" x 43" cosec(Dec.) and an rms noise level of about 1 mJy/beam. SUMSS is therefore similar in sensitivity and resolution to the northern NRAO VLA Sky Survey (NVSS; Condon et al...
Downloads: 7
[texts]Thin and fat sets for doubling measures in metric spaces - Tuomo Ojala
We consider sets in uniformly perfect metric spaces which are null for every doubling measure of the space or which have positive measure for all doubling measures. These sets are called thin and fat, respectively. In our main results, we give sufficient conditions for certain cut-out sets being thin or fat.
Downloads: 13
[texts]Geotropic tracers in turbulent flows: a proxy for fluid acceleration - Guido Boffetta
We investigate the statistics of orientation of small, neutrally buoyant, spherical tracers whose center of mass is displaced from the geometrical center. If appropriate-sized particles are considered, a linear relation can be derived between the horizontal components of the orientation vector and the same components of acceleration. Direct numerical simulations are carried out, showing that such relation can be used to reconstruct the statistics of acceleration fluctuations up to the order of t...
Downloads: 8
[texts]VLF observation during Leonid Meteor Shower-2002 from Kolkata - Sandip K. Chakrabarti
Using a Gyrator-II Loop antenna tuned at 19.0Khz, we monitored the meteor shower during 17-24th November, 2002. We observe the primary peak at 3h58m (UT) on the 19th of November, 2002. We distinctly observed several `beadlike' and `exponentially dropping' signals. The `beadlike' signals were more in abundance on the 18th of November, 2002, one day prior to the actual encounter.
Downloads: 9
[texts]Optimization of quasi-normal eigenvalues for Krein-Nudelman strings - Illya M. Karabash
The paper is devoted to optimization of resonances for Krein strings with total mass and statical moment constraints. The problem is to design for a given $\alpha \in \R$ a string that has a resonance on the line $\alpha + \i \R$ with a minimal possible modulus of the imaginary part. We find optimal resonances and strings explicitly.
Downloads: 15
[texts]Minimal duality breaking in the Kallen-Lehman approach to 3D Ising model: a numerical test - Marco Astorino
A Kallen-Lehman approach to 3D Ising model is analyzed numerically both at low and high temperature. It is shown that, even assuming a minimal duality breaking, one can fix three parameters of the model to get a very good agreement with the MonteCarlo results at high temperatures. With the same parameters the agreement is satisfactory both at low and near critical temperatures. How to improve the agreement with MonteCarlo results by introducing a more general duality breaking is shortly discusse...
Downloads: 12
[texts]Biogeography-Based Informative Gene Selection and Cancer Classification Using SVM and Random Forests - Sarvesh Nikumbh
Microarray cancer gene expression data comprise of very high dimensions. Reducing the dimensions helps in improving the overall analysis and classification performance. We propose two hybrid techniques, Biogeography - based Optimization - Random Forests (BBO - RF) and BBO - SVM (Support Vector Machines) with gene ranking as a heuristic, for microarray gene expression analysis. This heuristic is obtained from information gain filter ranking procedure...
Downloads: 12
[texts]Efficient Promotion Strategies in Hierarchical Organizations - Alessandro Pluchino
The Peter principle has been recently investigated by means of an agent-based simulation and its validity has been numerically corroborated. It has been confirmed that, within certain conditions, it can really influence in a negative way the efficiency of a pyramidal organization adopting meritocratic promotions. It was also found that, in order to bypass these effects, alternative promotion strategies should be adopted, as for example a random selection choice...
Downloads: 15
[texts]Observations of TeV gamma-rays from Mrk 421 during Dec. 2005 to Apr. 2006 with the TACTIC telescope - K. K. Yadav
The TACTIC $\gamma$-ray telescope has observed Mrk 421 on 66 clear nights from Dec. 07, 2005 to Apr. 30, 2006, totalling $\sim$ 202 hours of on-source observations. Here, we report the detection of flaring activity from the source at $\geq$ 1 TeV energy and the time-averaged differential $\gamma$-ray spectrum in the energy range 1-11 TeV for the data taken between Dec. 27, 2005 to Feb. 07, 2006 when the source was in a relatively higher state as compared to the rest of the observation period...
Downloads: 6
[texts]Evolution and Distribution of Magnetic Fields from AGNs in Galaxy Clusters II. The Effects of Cluster Size and Dynamical State - Hao Xu
Theory and simulations suggest that magnetic fields from radio jets and lobes powered by their central super massive black holes can be an important source of magnetic fields in the galaxy clusters. This is paper II in a series of studies where we present self-consistent high-resolution adaptive mesh refinement cosmological magnetohydrodynamic (MHD) simulations that simultaneously follow the formation of a galaxy cluster and evolution of magnetic fields ejected by an active galactic nucleus (AGN...
Downloads: 12
[texts]Z(3) Interfaces in Lattice Gauge Theory - S. T. West
A study is made of properties of the Z(3) interface which forms between the different ordered phases of pure SU(3) gauge theory above a critical temperature. The theory is simulated on a (2+1)-D lattice at various temperatures above this critical point. At high temperatures, the interface tension is shown to agree well with the prediction of perturbation theory. Near the critical temperature, the interface behaviour is characterised by various displacement moments, and modelled by an interacting...
Downloads: 26
[texts]Some new aspects of the coupon-collector's problem - Amy N. Myers
We extend the classical coupon collector's problem to one in which two collectors are simultaneously and independently seeking collections of $d$ coupons. We find, in finite terms, the probability that the two collectors finish at the same trial, and we find, using the methods of Gessel-Viennot, the probability that the game has the following ``ballot-like'' character: the two collectors are tied with each other for some initial number of steps, and after that the player who first gains the lead...
Downloads: 10
[texts]Generalized q-Onsager Algebras and Dynamical K-matrices - S. Belliard
A procedure to construct $K$-matrices from the generalized $q$-Onsager algebra $\cO_{q}(\hat{g})$ is proposed. This procedure extends the intertwiner techniques used to obtain scalar (c-number) solutions of the reflection equation to dynamical (non-c-number) solutions. It shows the relation between soliton non-preserving reflection equations or twisted reflection equations and the generalized $q$-Onsager algebras...
Downloads: 8
[texts]Periodic orbit action correlations in the Baker map - Gregor Tanner
Periodic orbit action correlations are studied for the piecewise linear, area-preserving Baker map. Semiclassical periodic orbit formulae together with universal spectral statistics in the corresponding quantum Baker map suggest the existence of universal periodic orbit correlations. The calculation of periodic orbit sums for the Baker map can be performed with the help of a Perron-Frobenius type operator...
Downloads: 14
[texts]Energy distribution and cooling of a single atom in an optical tweezer - C. Tuchendler
We investigate experimentally the energy distribution of a single rubidium atom trapped in a strongly focused dipole trap under various cooling regimes. Using two different methods to measure the mean energy of the atom, we show that the energy distribution of the radiatively cooled atom is close to thermal. We then demonstrate how to reduce the energy of the single atom, first by adiabatic cooling, and then by truncating the Boltzmann distribution of the single atom...
Downloads: 9
[texts]Observatories - Kevin Krisciunas
I give a brief history of astronomical observatories as an institution. This includes: 1) observatories in Islam; 2) China and India; 3) early European observatories; 4) the rise of national observatories; 5) private (amateur) observatories; 6) mountaintop observatories and the modern era. Additional references, to material not cited in the version that will be published in the encyclopedia, are also given.
Downloads: 22
[texts]Energetic Cosmic Rays observed by the resonant gravitational wave detector NAUTILUS - P. Astone
Cosmic ray showers interacting with the resonant mass gravitational wave antenna NAUTILUS have been detected. The experimental results show large signals at a rate much greater than expected. The largest signal corresponds to an energy release in NAUTILUS of 87 TeV. We remark that a resonant mass gravitational wave detector used as particle detector has characteristics different from the usual particle detectors, and it could detect new features of cosmic rays...
Downloads: 22
[texts]Primes in Geometric-Arithmetic Progression - Sameen Ahmed Khan
A geometric-arithmetic progression of primes is a set of $k$ primes (denoted by GAP-$k$) of the form $p_1 r^j + j d$ for fixed $p_1$, $r$ and $d$ and consecutive $j$, {\it i.e}, $\{p_1, \, p_1 r + d, \, p_1 r^2 + 2 d, \, p_1 r^3 + 3 d, \,...}$. We study the conditions under which, for $k \ge 2$, a GAP-$k$ is a set of $k$ primes in geometric-arithmetic progression. Computational data (along with the MATHEMATICA codes) containing progressions up to GAP-13 is presented...
Downloads: 22
[texts]Theory of Sorption Hysteresis in Nanoporous Solids: I. Snap-Through Instabilities - Zdenek P. Bazant
The sorption-desorption hysteresis observed in many nanoporous solids, at vapor pressures low enough for the the liquid (capillary) phase of the adsorbate to be absent, has long been vaguely attributed to changes in the nanopore structure, but no mathematically consistent explanation has been presented. The present work takes an analytical approach to account for discrete molecular forces in the nanopore fluid and proposes two related mechanisms that can explain the hysteresis at low vapor press...
Downloads: 14
[texts]Carnot's theorem for nonthermal stationary reservoirs - Simone De Liberato
Carnot's theorem poses a fundamental limit on the maximum efficiency achievable from an engine that works between two reservoirs at thermal equilibrium. We extend this result to the case of arbitrary nonthermal stationary reservoirs, even with quantum coherence. In order to do this we prove that a single nonthermal reservoir is formally equivalent to multiple equilibrium ones. Finally, we discuss the possibility of realizing an engine that works at unit efficiency by exploiting quantum coherence...
Downloads: 29
[texts]Some graphical aspects of Frobenius structures - Bertfried Fauser
We survey some aspects of Frobenius algebras, Frobenius structures and their relation to finite Hopf algebras using graphical calculus. We focus on the `yanking' moves coming from a closed structure in a rigid monoidal category, the topological move, and the `yanking' coming from the Frobenius bilinear form and its inverse, used e.g. in quantum teleportation. We discus how to interpret the associated information flow...
Downloads: 11
[texts]Impact of Supersymmetry on Emergent Geometry in Yang-Mills Matrix Models - Badis Ydri
We present a study of D=4 supersymmetric Yang-Mills matrix models with SO(3) mass terms based on the cohomological approach and the Monte Carlo method. In the bosonic models we show the existence of an exotic first/second order transition from a phase with a well defined background geometry (the fuzzy sphere) to a phase with commuting matrices with no geometry in the sense of Connes. At the transition point the sphere expands abruptly to infinite size then it evaporates as we increase the temper...
Downloads: 50
[texts]Dust Streamers in the Virgo Galaxy M86 from Ram Pressure Stripping of its Companion VCC 882 - D. M. Elmegreen
The giant elliptical galaxy M86 in Virgo has a ~28 kpc long dust trail inside its optical halo that points toward the nucleated dwarf elliptical galaxy, VCC 882. The trail seems to be stripped material from the dwarf. Extinction measurements suggest that the ratio of the total gas mass in the trail to the blue luminosity of the dwarf is about unity, which is comparable to such ratios in dwarf irregular galaxies...
Downloads: 6
[texts]Multi-Higgs boson production in the Standard Model and beyond - T. Binoth
We present a calculation of the loop-induced processes gg -> HH and gg -> HHH, and investigate the observability of multi-Higgs boson production at the CERN Large Hadron Collider (LHC) in the Standard Model (SM) and beyond. While the SM cross sections are too small to allow observation at the LHC, we demonstrate that physics beyond the SM can lead to amplified, observable cross sections. Furthermore, the applicability of the heavy top quark approximation in two- and three-Higgs boson production ...
Downloads: 9
[texts]Form factors of heavy-to-light B decays at large recoil - D. Ebert
General relations between the form factors of B decays to light mesons are derived using the heavy quark and large recoil expansion. On their basis the complete account of contributions of second order in the ratio of the light meson mass to the large recoil energy is performed. Both ground and excited final meson states are considered. It is shown that most of the known form factor relations remain valid after the inclusion of quadratic mass corrections...
Downloads: 25
[texts]Large deviation for return times in open sets for axiom A diffeomorphisms - Renaud Leplaideur
For axiom A diffeomorphisms and equilibrium state, we prove a Large deviation result for the sequence of successive return times into a fixed open set, under some assumption on the boundary. Our result relies on and extends the work by Chazottes and Leplaideur who where considering cylinder sets of a Markov partition.
Downloads: 8
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